\(-45\%x+2\dfrac{3}{8}=-1\dfrac{31}{40}\)
\(\Rightarrow-\dfrac{9}{20}x+\dfrac{19}{8}=-\dfrac{71}{40}\)
\(\Rightarrow-\dfrac{9}{20}x=-\dfrac{71}{40}-\dfrac{19}{8}\)
\(\Rightarrow-\dfrac{9}{20}x=-\dfrac{83}{20}\)
\(\Rightarrow x=-\dfrac{83}{20}:\left(-\dfrac{9}{20}\right)\)
\(\Rightarrow x=\dfrac{83}{9}\)
Vậy \(x=\dfrac{83}{9}\)
\(-45\%x+2\dfrac{3}{8}=-1\dfrac{31}{40}\)
\(\Leftrightarrow\dfrac{9}{20}x+\dfrac{19}{8}=-\dfrac{71}{40}\)
\(\Leftrightarrow\dfrac{9}{20}x=-\dfrac{71}{40}-\dfrac{19}{8}\)
\(\Leftrightarrow\dfrac{9}{20}x=-\dfrac{83}{20}\)
\(\Leftrightarrow x=-\dfrac{83}{20}:\dfrac{9}{20}\)
\(\Leftrightarrow x=-\dfrac{83}{20}.\dfrac{20}{9}\)
\(\Leftrightarrow x=-\dfrac{83}{9}\)
